Among other things, season 5 was defined by its big events, which were easily among the biggest the show has ever seen. Many of these events directly contributed to the altered status quo of season six, and in a season of big changes, easily the biggest was in "Crusaders of the Lost Mark," which featured Cutie Mark Crusaders obtaining their cutie marks. With that long-running story arc out of the way, the question opened of what would be done with those characters next. "On Your Marks" attempts to answer that question, picking up the new story arc for the Crusaders which was set up in "Crusaders" while attempting to focus on the individual characters' development. The results are decidedly imperfect, and yet, "On Your Marks" is perhaps the most purely enjoyable episode of season 6 yet.
First and foremost, "On Your Marks" attempts to confront what will happen to the Cutie Mark Crusaders as a club now that they have their cutie marks. Specifically, the CMC try to figure out what to do now that their previous hobby isn't possible. Eventually, they find that their immediate interests have relatively little overlap, and so they decide to start doing their own things. Unfortantely, Apple Bloom misinterprets the suggestion, and while her friends are trying fun new things, she's desperately struggling to find anything that interests her. Having the CMC explore their interests separately gives the pretty solid message that you don't need to do everything with your friends, and if your interests divert from your friends', that's okay.
The episode also picks up the new goal of the CMC as shown in "Crusaders of the Lost Mark," in that they try (and fail) to find cutie mark problems to fix. Eventually a real cutie mark problem does arise, but this is barely confronted until the episode's climax, and instead the bulk of the episode is focused on the CMC figuring out what to do now that they have their marks. In a sense, this makes the episode is simpler than the previous two, in part because it doesn't delve as deep into the characters as the previous episode and in part because Apple Bloom's character arc, which is the clear centrepiece of the episode, doesn't reach a definite conclusion.
In fact, if the episode has one significant problem, it's that it's not about anything. Thematically, it barely goes anywhere, and narratively, it shows characters' lives changing but doesn't do a whole lot with that. While the main conflict is about Apple Bloom figuring out what she'll do on her own, this ultimately serves as little more than a buildup to the introduction of a new character, a dancer who hasn't found his cutie mark. Although this character thankfully doesn't take attention away from Apple Bloom, his story arc doesn't connect all that meaningfully to the main plot leading up to it. At the very least, it does coincide with Apple Bloom deciding to take up dancing, but the two conflicts never really connect.
While Apple Bloom is the least interesting of the Crusaders, "On Your Marks" does make a valiant effort to give her interesting character traits. One of her biggest struggles in finding something to do without her friends is that she strongly prefers activities done with others, and every attempt to do something on her own only caused her to feel lonely. On a more minor note, she is shown to have become fond of potion-making, which is presumably something she always did with Zecora or Twilight. One thing that doesn't work as well, however, is her complete misunderstanding of what her friends mean by doing their own things. It appears that Apple Bloom believes that she and her friends won't be doing stuff together anymore, but nothing is made of that. Perhaps it only exists for the ultimate lesson that it's okay to do fun things without your friends, but that's not the show's strongest aesop.
However, despite the episode's issues, it remains thoroughly entertaining. While it's still not the most gut-busting or exciting episode, it's got more than its fair share of solid gags, and because it has less going on than its predecessors, there's more space for it to be straightforwardly fun. The Crusaders have solid interactions, there are plenty of solid visual gags, and the main plot is charming even with its issues. The pacing is brisk, which contributes to the episode's entertainment value but is also at points detrimental to character development. Parts of Apple Bloom's arc feel skimmed over, and as such they lose much of their impact.
"On Your Marks" retains the season's trend of freshening up the show with new plots and developments in the status quo, and yet it doesn't quite possess the focus of the previous two episodes. There's a definite attempt to continue the momentum given these characters by the last season, but this episode doesn't quite fulfil its potential. Its main arc is flawed and it doesn't push the CMC forward as much as it might have. And yet, for all of its issues, "On Your Marks" remains entertaining. It's a fun episode that stops short of being great, boasting interesting ideas that aren't fully fleshed out but dressing them in enough solid character moments and gags as to greatly compensate for the episode's imperfections. Perhaps the potential of the synopsis got my expectations too high, but although "On Your Marks" is a relative disappointment, it's enjoyable in its own right.